[0001] This invention relates to the improvement of a steering column in the cab of an agricultural
combine harvester. More specifically it relates to a steering column which may be
adjusted in four directions.
[0002] Mechanical harvesting of grain has taken place for decades. However, efforts continue
in the attempt to make harvesting operations more efficient and effective. A combine
harvester generally includes a header which cuts the crop. The header than moves the
cut crop into a feeder house, which lifts the cut crop into the threshing and separation
areas of the combine. The grain is separated from the stalk by a rotor. The grain
is then moved and stored in a grain tank. The chaff and trash is deposited from the
rear of the combine. An operator usually runs these various operations from a glass-enclosed
cab. Typically, a cab is located behind the cutting header and in front of the threshing
and separation areas of the combine. An operator can observe most of the combine activities
from the cab. During harvesting periods it is not uncommon for the combine to be operated
for an extended time. Sometimes a single operator will use a combine for 16 to 18
hours a day. Furthermore, several operators may alternate in the use of the combine.
Therefore is it necessary to provide a cab which will allow maximum operator comfort
and flexibility. This will permit the operator to remain mentally alert for the long
time intervals needed to harvest crops. One aspect of maintaining the operator's alertness
is to provide a steering column that may be manipulated to a comfortable position.
Equally important is to provide a steering column which is located in a manner to
allow an unobstructed view of the various combine operations. It would also be advantageous
to provide a steering column which would be suitable to different sized individuals.
Finally it would be desirable to provide an steering column that is relatively impervious
to the harsh off-road environment common in farming operations.
[0003] The effort to design and manufacture an acceptable steering column for farm operations
is considerable. The research effort has followed several paths. Many steering columns
use a single telescoping portion. This feature allows the steering wheel to be moved
either closer or further from the operator. An additional improvement provides for
a pivot assembly to allow the column to be positioned in a variety of angles. Initially,
a ratchet mechanism has been used to control the pivoting motion. Later, gas cylinders
were introduced to allow the steering column to be positioned in infinite range of
angles. However, each of these approaches has limitations and drawbacks. Typically,
these steering columns were placed in automobiles into a vertical wall, such as the
firewall. Therefore, it is necessary to provide only a steering column with two ranges
of motion (rotation around the pivot axis and translation along the steering column).
However, in a harvester combine such a design is undesirable. The placement of a steering
column on a vertical surface would obstruct the operator's view of the header. It
is possible to affix a steering column to the horizontal cab floor. However, it is
difficult for operators of different sizes to position the steering column in manner
which is both comfortable and which does not obstruct the view.
[0004] The prior art illustrates these and additional difficulties. US-A-4,733,745 discloses
an adjustable control attachment for an earth moving vehicle. The steering column
is capable of rotation around the base. The drawback to this design is that a smaller
individual would need to move the operator's seat rearward, this would move the operator
away from any floor pedals. Additionally, the lower portion of the steering column
may obstruct the operator's view.
[0005] US-A-4,993,279 discloses a tilt steering column latch release. This column again
has a single pivot axis, but also possesses a release mechanism to allow the steering
column to move to a lower position to allow easy maintenance.
[0006] US-A-5,088,342 discloses a pivotable steering wheel mechanism and biasing means.
The steering column again possesses a single pivoting point which could limit the
operator's range of vision.
[0007] US-A-5,168,768 discloses a tilt steering column assembly. The steering column has
a single pivot and is capable of being moved back into the original position after
being moved.
[0008] US-A-5,035,446 and US-A-4,972,732 disclose tilt-telescope steering column for automobiles.
Both devices are designed to be attached to a vertical surface. The steering column
can telescope and can tilt. The lower portion of the column is fixed and could obstruct
an operator's view.
[0009] Consequently, the need exists for a steering column which will provide an unobstructed
view of farming operations by being able to move in four directions.
[0010] According to the invention, there is provided an adjustable floor mounted steering
column comprising:
a base support affixed to a substantially horizontal floor, said support having a
steering motor;
a lower pivot assembly, pivotally affixed to the base support for enabling pivotal
movement of said lower pivot assembly about a lower horizontal axis;
an upper pivot assembly, pivotally affixed to the lower pivot assembly for enabling
pivotal movement of said upper pivot assembly to said lower pivot assembly about an
upper horizontal axis; and
an input shaft located substantially coaxially with the upper pivot assembly, the
lower pivot assembly and base support, said input shaft having a steering wheel and
being affixed to the steering motor, thereby transmitting a rotational force placed
on the steering wheel, to the steering motor;
characterized in that:
said input shaft comprises an upper telescoping shaft to which said steering wheel
is affixed and which enables translation of said steering column in a direction defined
by the axis of said telescoping shaft; and
said lower pivot assembly comprises slideable means, which enable translation of said
steering column in a direction defined substantially by the longitudinal axis of said
slideable means.
[0011] Consequently there is provided a floor mounted steering column which has two pivot
axes and two telescoping sections.
[0012] For ease of operation, gas cylinders may be used to alter the position of the steering
column. Such cylinders may be controlled by means of a foot pedal.
[0013] Such steering column can accommodate a variety of individuals regardless of their
size.
[0014] The use of an input shaft comprising universal joints enables transmission of the
rotation placed on the steering wheel to a steering motor, even if the column has
two pivot points.
[0015] Advantageously a cover may be provided, which can be placed over the steering column
thus preventing damage to the mechanism. Such cover preferably covers the steering
column regardless of the position the column is placed. The cover may comprise a flexible
boot surrounding the base support. Preferably, above the boot is a non-flexible lower
cover with a lower region and first concave portion. The lower region is inserted
into the boot. Above the lower cover is the non-flexible middle cover with a second
concave portion and upper region. The second concave portion generally covers the
first concave portion. The upper region is inserted into an upper cover.
[0016] An upper locking knob on the steering wheel may allow the upper telescoping shaft
to telescope upward or downward.
[0017] By way of example, an elongated key on the exterior circumference of the inner input
shaft transfers the torque to a key slot on the interior circumference of the outer
input shaft. The outer input shaft is connected to the lower input shaft which is
connected to the steering motor.
[0018] The lower pivot assembly is also capable of telescoping upwards or downwards by loosening
the lower locking knob.
[0019] A steering column in accordance with the present invention will now be described
in further detail, by way of example, with reference to the following drawings, in
which:
Figure 1 is a general view of a combine harvester combine with a cab containing a
steering column;
Figure 2 is side view of the cab illustrating the prior art steering column arrangement;
Figure 3 is a side view of the cab illustrating a steering column according to the
present invention, with the steering column in a stowed position for entrance and
egress to the operator's seat;
Figure 4 is a side view of the cab illustrating the steering column of Figure 3 in
the convention driving position, the phantom lines illustrating the ability for the
operator to tilt or telescope the upper shaft;
Figure 5 is a side view of the cab illustrating the steering column of Figure 3 in
the horizontal driving position for an operator having a small build;
Figure 6 is a side view of the cab illustrating the steering column of Figure 3 in
the horizontal driving position for an operator having a large build;
Figure 7 is an exploded view of the steering column of Figure 3;
Figure 8 is a front view of the steering column of Figure 3 showing the covers;
Figure 9 is an enhanced view of the lower locking knob, first lower telescoping shaft,
second lower telescoping shaft, outer input shaft and inner input shaft; and
Figure 10 is a view illustrating the range of motion of the steering column.
[0020] Referring to the drawings, it is possible to observe the major elements and general
operation of the present invention. Left and right references are used as a matter
of convenience and are determined by standing at the rear of the combine and facing
the forward end in the normal direction of travel. Likewise, forward and rearward
are determined by normal direction of travel of the combine. Upward or downward orientations
are relative to the ground or operating surface. Horizontal or vertical planes are
also relative to ground.
[0021] The steering column 10 is located within the cab 2 of a combine 1. A typical combine
has a header 18 for cutting a crop. As the combine 1 and header 18 are moved forward,
the grain and stalk are cut by the header. The header 18 moves the grain into an auger
trough. A transverse auger pushes the grain and stalk in the auger trough to the centre
of the header. Located at the centre of the header is the feeder house or elevator.
The feeder house moves the grain and stalk rearward into the threshing and separation
systems of the combine 1. After processing and separation, the processed grain is
stored in a grain tank located near the top of the combine. The trash or chaff is
ejected from the rear of the combine. The operator runs the combine 1 from the cab
2 located behind the header 18 and at the front of the combine. From the cab the operator
can observe most the various combine functions. The cab 2 usually has a large glass
window or several windows which afford the operator the maximum ability to monitor
the header 18. Located in the centre of the cab 2 is the steering column 10 with a
steering wheel 90 attached. By turning the steering wheel 90, the operator manipulates
various elements within the steering column 10 which, in turn, controls a steering
motor 24 which turns the wheels of the combine. Located behind the steering column
10 is an operator's chair. The prior art steering column is illustrated by Figure
2. The operation has a partially obstructed view 17 when looking downwards and out
of the cab. This steering column is blocking a portion of the operator's view.
[0022] A steering column 10 accordance to the invention is shown in Figure 3. The steering
column 10 is located within the cab 2 of the combine 1. The steering column is affixed
to the horizontal cab floor 3 by the base support 20. Above the base support 20 is
the lower pivot assembly 30. Above the lower pivot assembly 30 is the upper pivot
assembly 60. Running coaxially with the upper pivot assembly 60, lower pivot assembly
30 and base support 20 is the input shaft 110 (Figure 7). Attached to the input shaft
110 is the steering wheel 90. The opposite end of the input shaft 110 is connected
to the steering motor 24 located beneath the base support 20. The column 10 is capable
of four types of motion. The input shaft 110 near the steering wheel 90 can telescope
up and down and part of the steering column near the lower pivot assembly 30 can also
telescope up and down. Furthermore, the column 10 can rotate about pivot located between
the base support 20 and the lower pivot assembly 30. Part of the column 10 can also
rotate about a pivot located in the upper pivot assembly 60. The entire assembly,
regardless of position or height is protected by a cover. These items will be discussed
in greater detail below. The range of motion offered by the steering column 10 enables
the steering wheel 90 to be positioned in a manner to provide an unobstructed view
17 of the header 18. This is true regardless of whether the individual has a small
build 16 (Figure 5) or large build 15 (Figure 6). Further, the steering column 10
may be positioned so that the steering wheel 90 can be in a conventional operating
position 14 (Figure 4) or a horizontal operating position 12 or 13 (Figures 5 and
6). The horizontal operating position offers the driver maximum comfort and unobstructed
view for an extended time period.
[0023] Affixed to the horizontal cab floor 2 is the base support 20. Located beneath the
base support 20 is the steering motor 24. The steering motor 24 moves the combine
wheels. Attached to the base support 20 is pedal stop 21. The pedal stop 21 is pivotally
attached to the base support 20. Attached to the pedal stop is a pedal spring 25.
Attached to the side of the pedal stop 21 is the foot pedal 22. The foot pedal 22,
pedal stop 21 and pedal spring 25 actuate the lower gas cylinder 37. The lower gas
cylinder 37 will be discussed in more detail later.
[0024] The input shaft 110 comprises several pieces. The upper telescoping shaft 111 is
located within the upper input shaft 112. The upper telescoping shaft 111 and upper
input shaft 112 are conventional telescoping shafts manufactured by a variety of sources.
In the preferred embodiment, the shafts are manufactured by Douglas Autotech Corp.
of Bronson, MI and have parts no. 48528, 48527, 48197 and 48188. Attached to the upper
telescoping shaft 111 is the steering wheel 90. By turning the upper locking knob
91 located in the centre of the steering wheel, the upper telescoping shaft 111 can
be raised or lowered relative to the upper input shaft 112. Affixed to the upper input
shaft 112 is the first universal joint 116. The first universal joint 116 connects
the upper input shaft 112 to the inner input shaft 113. The inner input shaft 113
has a torque transfer means illustrated as an elongated key 118, on its exterior circumference
120. Surrounding the inner input shaft 113 is the outer input shaft 114. A torque
receiving means illustrated as key slot 121 is located on the interior circumference
119 of the outer input shaft. The inner input shaft 113 is capable of moving up or
down relative to the outer input shaft 114. The elongated key 118 which is inserted
into the key slot 121 transfers the rotation of the inner input shaft 113 to the outer
input shaft 114. Attached to the outer input shaft 114 is the second universal joint
117. The second universal joint 117 connects the outer input shaft 114 to the lower
input shaft 115. The lower input shaft 115 is connected to the steering motor 24.
The lower input shaft may also have an elastic isolator 123 for dampening vibrations
from the steering motor 24 and the rest of the combine 1.
[0025] The lower pivot assembly 30 consists of a first lower telescoping shaft 31 and a
second lower telescoping shaft 34. The first lower telescoping shaft 31 surrounds
the second lower telescoping shaft 34. The first lower telescoping shaft 31 slides
relative to the second lower telescoping shaft 34. Within and coaxial to the second
lower telescoping shaft 34 is the outer input shaft 114 and the inner input shaft
113. The second lower telescoping shaft 34 is attached to the lower sub-assembly 35.
The lower sub-assembly 35 is pivotally attached to the base support 20. The second
universal joint 117 is aligned at the pivot point between the lower sub-assembly 35
and base support 20. Also attached to the lower sub-assembly 35 is the lower cylinder
mount 36. The second lower telescoping shaft 34 has vertical groove 32. The first
lower telescoping shaft 31 has four cover attachment mounts 45. Additionally, the
first lower telescoping shaft 31 has a threaded bore 41. Inserted in the threaded
bore 41 is the clamping washer 42. A lower locking knob 33 is used in conjunction
with the threaded bore 41, the clamping washer 42 and vertical groove 32 to prevent
the first lower telescoping shaft 31 from sliding or rotating about the second lower
telescoping shaft 34. The lower locking knob 33 has a threaded portion 44 and a shoulder
43 at the tip. The shoulder 43 is inserted into the threaded bore 41, clamping washer
42 and vertical groove 32. The threaded portion 44 and threaded bore 41 are tightened.
This forces the clamping washer 42 against the second lower telescoping shaft 34 preventing
the first lower telescoping shaft from translating up or down. The shoulder 43 within
the vertical groove 32 prevents the first lower telescoping shaft 31 from rotating
about the second lower telescoping shaft 34. In a secondary embodiment, a lift assist
spring 122 is placed about the second lower telescoping shaft 34. The spring 122 exerts
an upward force on the first lower telescoping shaft 31 making it easier to translate
when the lower locking knob 33 is loosened.
[0026] Affixed to the first lower telescoping shaft 31 is the upper pivot assembly 60. The
upper pivot assembly 60 has an upper sub-assembly 64 and an upper shaft 61 pivotally
affixed to the first lower shaft 31. The first universal joint 116 is aligned at the
pivot point between upper sub-assembly 64 and upper shaft 61. Attached to the upper
sub-assembly 64 is the upper cylinder mount 65. Attached to the upper shaft 61 is
the control bracket 62 and the upper rod mount 66. Surrounding the upper shaft 61
is the upper cover 63. The upper input shaft 112 and upper telescoping shaft 111 are
located within and coaxially to the upper shaft 61.
[0027] The upper gas cylinder 67 has an upper cylinder attach 70, an upper valve actuator
68, an upper rod mount 66 and an upper tilt lever 69. The upper cylinder attach 70
is pivotally attached to the upper cylinder mount 65 on the upper sub-assembly 64.
The upper valve actuator 68 is pivotally attached to the upper rod mount 66. The upper
tilt lever 69 controls the upper valve actuator 68. By moving the upper tilt lever
69, the gas cylinder 67 may be lengthened or shortened. This results in the upper
shaft 61 pivoting, as illustrated by arrow 5 in Figure 10, about the upper sub-assembly
64. By using a gas cylinder, the upper shaft 61 may be pivoted (arrow 5) relative
to the upper sub-assembly to an infinite number of positions. Relative the upper sub-assembly
64, the upper shaft 61 can rotate a total of 50 degrees. In the preferred embodiment,
the range, measured from the vertical axis is 35 degrees in the forward rotation and
15 degrees in a rearward rotation. The 35 degree forward rotation is denoted by β
in Figure 10 and the 15 degree rearward rotation is denoted by χ in Figure 10.
[0028] The lower gas cylinder 37 has a lower cylinder attach 38 and a lower valve actuator
40. The lower cylinder attach 38 is pivotally attached to the lower cylinder mount
36. The lower valve actuator 40 is attached to the base support 20. The lower valve
actuator 40 is controlled by the pedal stop 21. The pedal stop 21 is controlled by
the foot pedal 22. The pedal stop 22 and pedal spring 25 prevent an operator from
placing too great a force on the foot pedal 22 that might damage the lower gas cylinder
37. When an operator depresses the foot pedal 22, a force sufficient to operate the
lower valve actuator 40 is received by the valve. The excess force is transmitted
to the pedal stop 21. The spring 26 returns the pedal 21 to its normal position. By
depressing the foot pedal 22, the lower gas cylinder 37 may be lengthened or shortened.
This results in the lower pivot assembly 30 pivoting as indicated by arrow 4 in Figure
10, about the base support 20. By using a gas cylinder, the lower pivot assembly 30
may be pivoted relative to the base support 20 to an infinite number of positions.
Relative to the base support 20, the lower pivot assembly 30 can rotate (arrow 4)
a total of 42 degrees. In the preferred embodiment, the range, measured from the vertical
axis is 0 degrees in the forward rotation and 42 degrees in a rearward rotation. This
is indicated by α in Figure 10.
[0029] The steering column 20 has several protective covers to protect its elements. There
is a flexible boot 131 attached to the horizontal cab floor 3 and surrounding the
base support 20. Above the flexible boot 131 is the non-flexible lower cover 128 a
and 128 b. Figure 8 illustrates the lower cover 128 before final assembly. The lower
cover, prior to final assembly consists of a left-side 128 a and a mirror image right-side
128 b. In the preferred embodiment, the assembled non-flexible lower cover 128 is
composed of a hard plastic. The lower cover 128 consists of a lower region 130 (a
and b) and a first concave portion 129 (a and b). The first concave portion 129 (a
and b) is generally spherically shaped. The lower cover 128 is attached to the cover
attachment mounts 45 on the first lower telescoping shaft 31. The four attachment
points are located in the lower region 130. The rim of lower region 130 is placed
inside of the flexible boot 131. As the first lower telescoping shaft 31 moves relative
to the second lower telescoping shaft 34, the lower cover 128 remains positioned over
the both shafts.
[0030] Above the non-flexible lower cover 128 is the non-flexible middle cover 125. Figure
8 illustrates the front 125 a and mirror-image rear 125 b of the middle cover prior
to final assembly. In the preferred embodiment, the non-flexible middle cover 125
is composed of a hard plastic. The middle cover 125 (a and b) consists of an upper
region 126 (a and b) and a second concave portion 127 (a and b). The second concave
portion 127 is generally spherically shaped and partially encompasses the first concave
portion 129. The middle cover 125 is attached near the upper shaft 61 and the control
bracket 62. The upper region 126 is placed inside of the upper cover 63. As the upper
telescoping shaft 111 moves relative to the upper input shaft 112, the middle cover
125 remains positioned over both shafts. The second concave portion 127 is able to
rotate over the first concave portion 129. The second concave portion 127 protects
the top of the first concave portion 129.
[0031] To operate the steering column 10, the operator places a rotational force 11 (Figure
5) on the steering wheel 90. The force 11 is transmitted to the input shaft 110. The
upper telescoping shaft 111 is attached to the upper input shaft 112 which is attached
to the first universal joint 116. The first universal joint 116 is connected to the
inner input shaft 113. The elongated key 118 transmits the torque to the key slot
121 in the outer input shaft 114. The outer input shaft is connected to the second
universal joint 117. The second universal joint 117 is attached to the lower input
shaft 115. The lower input shaft 115 is connected to the steering motor 24.
[0032] The steering column 10 can be adjusted in four ways as illustrated in Figure 10.
The upper telescoping shaft 111 can translate relative to the upper input shaft 112
(see arrow 6) to raise or lower the steering wheel 90. This is accomplished by loosening
the upper locking knob 91 on the steering wheel 90. The first lower telescoping shaft
31 can translate relative to the second lower telescoping shaft 34 (see arrow 7) to
raise or lower the upper pivot assembly 60, upper input shaft 112, upper telescoping
shaft 111 and the steering wheel 90. This is accomplished by loosening the lower locking
knob 33. The steering column 10 is capable of rotating about the upper pivot assembly
60. This is accomplished by moving the upper tilt lever 69. This actuates the upper
gas cylinder 67 causing the cylinder to lengthen or shorten. This causes the upper
shaft 61 to pivot relative to the upper sub-assembly 64. The steering column 10 is
also capable of rotating about the base support 20 and lower pivot assembly 30. This
is accomplished by depressing the foot pedal 22. This actuates the lower gas cylinder
37 causing the cylinder to lengthen or shorten. This causes the lower sub-assembly
35 to pivot relative to the base support 20. The steering column can be positioned
in a conventional steering position 14 (Figure 4) or in a horizontal steering position
12 or 13 (Figures 5 and 6). The steering column can be positioned for a small individual
16 or an large individual 15. The horizontal operating position offers the most comfortable
steering position without an obstructed view. The steering column 10 can also be positioned
to allow easy entrance and egress from the cab 2 as illustrated in Figure 3. The second
lower telescoping shaft 34 is oriented in a vertical (0 degrees) position and the
upper shaft is oriented at minus 35 degree position (whereby the steering wheel is
forward of the vertical axis). This allows for the operator to reach or depart the
seat. Figure 10 illustrates the range of motion of the steering column. Figure 10
A shows the rotation 4 about the lower pivot assembly 30 and the base support 20 while
the lower telescoping shafts are fully extended (arrow 7). The upper telescoping shafts
can be translated to several positions as indicated by arrow 6. The upper telescoping
shafts rotates (arrow 5) to a range β + χ (50 degrees). The range is minus 35 degrees
(β) towards the front of the cab and measured from the vertical axis. The range is
15 degrees (χ) towards the rear of the cab and measured from the vertical axis. Figure
10 B shows the lower telescoping shafts retracted (arrow 7). However, the rotation
4 of the lower telescoping sections and the rotation 5 of the upper telescoping shafts
remain the same. The translation 7 of the lower telescoping shafts can be adjusted
to an infinite range (as can the translation 6 of the upper telescoping shafts).
[0033] It will be obvious to those skilled in the art that various changes may be made without
departing from the scope of the invention and the invention is not to be considered
limited to the embodiment illustrated in the drawings and described in the specification.
1. An adjustable floor mounted steering column (10) comprising:
a base support (20) affixed to a substantially horizontal floor (3), said support
having a steering motor (24);
a lower pivot assembly (30), pivotally affixed to the base support (20) for enabling
pivotal movement (4) of said lower pivot assembly (30) about a lower horizontal axis;
an upper pivot assembly (60), pivotally affixed to the lower pivot assembly (30) for
enabling pivotal movement of said upper pivot assembly (60) to said lower pivot assembly
(30) about an upper horizontal axis; and
an input shaft (110) located substantially coaxially with the upper pivot assembly
(60), the lower pivot assembly (30) and base support (20), said input shaft (110)
having a steering wheel (90) and being affixed to the steering motor (24), thereby
transmitting a rotational force (11) placed on the steering wheel (90), to the steering
motor (24);
characterized in that:
said input shaft (110) comprises an upper telescoping shaft (111) to which said steering
wheel (90) is affixed and which enables translation (6) of said steering column (10)
in a direction defined by the axis of said telescoping shaft (11); and
said lower pivot assembly (30) comprises slideable means (31, 34), which enable translation
(7) of said steering column (10) in a direction defined substantially by the longitudinal
axis of said slideable means (31, 34).
2. An adjustable steering column according to claim 1, characterized in that in that
it further comprises:
a lower gas cylinder (37) connected to the base support (20) and the lower pivot assembly
(30) and operable to pivot said lower pivot assembly (30) about the lower horizontal
axis when actuated; and/or
an upper gas cylinder (67) connected to the upper pivot assembly (60) and operable
to pivot said upper pivot assembly (60) about the upper horizontal axis when actuated.
3. An adjustable steering column according to claim 2, characterized in that:
said slideable means (31, 34) comprise a first lower telescoping shaft (31) and a
second lower telescoping shaft (34), located coaxially with the first lower telescoping
shaft (31), the common axis of which defining said direction of translation (7) of
said steering column (10).
4. An adjustable steering column according to claim 3, characterized in that said lower
pivot assembly (30) further comprises a lifting assist spring (122) located coaxially
with the second lower telescoping shaft (34), whereby the first lower telescoping
shaft (31) can be lifted.
5. An adjustable steering column according to claim 3 or 4, characterized in that:
said upper pivot assembly (60) comprises an upper sub-assembly (64), affixed to the
first lower telescoping shaft (31), and an upper shaft (61) pivotally affixed to said
upper sub-assembly (64);
a lower gas cylinder (37) connects the base support (20) and the second lower telescoping
shaft (34); and
an upper gas cylinder (67) connects said upper sub-assembly (64) and said upper shaft
(61).
6. An adjustable steering column according to claim 5, characterized in that:
said second lower telescoping shaft (34) has a longitudinal groove (32) therein; and
said lower pivot assembly (30) further comprises:
a lower sub-assembly (35) affixed to the second lower telescoping shaft (34);
a lower locking knob assembly having a pilot (33), a shoulder (43), a threaded portion
(44) and a clamping washer (42); and
said first lower telescoping shaft (31) having a threaded bore (41) therein for receiving
the clamping washer (42), whereby the first lower telescoping shaft (31) translates
(7) over the second lower telescoping shaft (34), the pilot (33) being inserted into
the threaded bore (41) through the clamping washer (42) and into the longitudinal
groove (32) so that the threaded portion (44) and the threaded bore (41) clamp the
clamping washer (42) on the second lower telescoping shaft (34) so as to prevent translation
(7) and rotation between the first lower telescoping shaft (31) and second lower telescoping
shaft (34).
7. An adjustable steering column according to claim 5 or 6, characterized in that:
said upper shaft (61) has an upper cover (63), a control bracket (62) and upper rod
mount (66), said upper cover (63) being coaxial to the upper shaft (61);
said upper sub-assembly (64) has an upper cylinder mount (65); and
the upper gas cylinder (67) further comprises:
an upper cylinder attach rod (70) which is pivotally affixed to the upper cylinder
mount (65); and
an upper valve actuator (68) pivotally affixed to the upper rod mount (66), said valve
actuator (68) being controlled by an upper tilt lever (69).
8. An adjustable steering column according to any of the claims 5 to 7, characterized
in that:
the base support (20) further comprises:
a pedal stop (21) pivotally affixed to the base support (20);
a pedal spring (25) affixed to the pedal stop (21); and
a foot pedal (22) affixed to the pedal stop (21);
said lower sub-assembly (35) has a lower cylinder mount (36); and
the lower gas cylinder (37) further comprises:
a lower cylinder attach rod (38) which is pivotally affixed to the lower cylinder
mount (36); and
a lower valve actuator (40) pivotally affixed to the pedal stop (21), said valve actuator
(40) being controlled by the foot pedal (22).
9. An adjustable steering column according to any of the claims 5 to 8, characterized
in that:
said first lower telescoping shaft (31) has a plurality of cover attachment mounts
(45); and
the column (10) further comprises:
a flexible boot (131) affixed to the floor (3);
a non-flexible lower cover (128) with a lower region (130) and a first concave portion
(129), said lower cover (128) being located coaxially with the first lower telescoping
shaft (31) and being affixed to the cover attachment mounts (45), a rim of said lower
region (130) being inserted within the flexible boot (131); and
a non-flexible middle cover (125) having an upper region (126) and a second concave
portion (127) and being located coaxially with the upper shaft (61), said second concave
portion (127) partially surrounding the first concave portion (129) and said upper
region (126) being inserted within an upper cover (63) coaxial to said upper shaft
(61).
10. An adjustable steering column according to any of the preceding claims, characterized
in that said input shaft (110) further comprises:
an inner input shaft (113), connected either directly or indirectly to the upper telescoping
shaft (111) by a first universal joint (116) and having a torque transfer means (118)
located on an exterior circumference (120) thereof;
an outer input shaft (114), located coaxially to the inner input shaft (113) and slideably
connected thereto, the outer input shaft (114) having a torque receiving means (121)
located on an interior circumference (119) thereof; and
a lower input shaft (115) connected to the outer input shaft (114) by a second universal
joint (117), the lower input shaft (115) being connected to the steering motor (24).
11. An adjustable steering column according to claim 10, characterized in that the lower
input shaft (115) has an elastic isolator (123).
12. An adjustable steering column according to claim 10 or 11, characterized in that said
torque transfer means (118) comprises an elongated key and said torque receiving means
(121) comprises a key slot whereby the elongated key (118) is inserted into the key
slot (121).
13. An adjustable steering column according to any of the preceding claims, characterized
in that an angle (α) defined by a vertical axis from the floor (3) and the longitudinal
axis of said slideable means (31, 34) is in a range of 0 to 42 degrees.
14. An adjustable steering column according to any of the preceding claims, characterized
in that an angle (β/χ) defined by a vertical axis from the floor (3) and the upper
telescoping shaft (111) is in a range of minus 35 degrees to 15 degrees.
15. An adjustable steering column according to any of the preceding claims, characterized
in that the upper telescoping shaft (111) is controlled by an upper locking knob (91).
16. A combine harvester, characterized in that it comprises a cab (2) having a steering
column (10) according to any of the preceding claims.